Edit: this is for my 81 300SD

I was so excited to try my new pressure brake bleeder until I pumped it up, and brake fluid squirted all over out the top of my brake fluid reservoir. It would appear there are two overflow valves at the top, how do I use the pressure bleeder without making fluid burst out of these valves?

Which car JohnDoe?

I'm not aware of overflow valves on master cylinder reservoirs but hey my knowledge is pretty limited - are you talking about brake fluid level sensors?

At what pressure are you operating your power bleeder?

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

It happens at a very low pressure, just one or two pumps, about 5psi. I guess it could be level sensors, they both have electrical wires connected, I'll take a picture tomorrow

I just did a Google image search and see two black caps that cover what I'm calling valve , I guess I need those caps, anyone know where to get them,?

I have experienced this same thing and ended up getting new ones from the dealer.

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Jim

If they leak, replace them.

Jeremy

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"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

I have had good luck using the Mighty Vac Tool with a Glass Jar I made up to Hold the Fluid inbetween.
I also have hooked the Mighty Vac to the Bleed Screw and pumped a little and soved a vacuum hose over the slightly loose Bleed Screw and simply walked away and let Gravity and time do the job.

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84 300D, 82 Volvo 244Gl Diesel

Phil got some for me. See if Peach still has them available. I don't remember whether they were a dealer part or not.

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

JohnDoe, Just a little advice. If I read a post and the year,make,model is not mentioned, I just bypass it. I'm sure I am not the only one. The ones that do answer a question and not even know what you are working on could be wrong. Take their advice with caution.

Paul

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84 500 SEL (307,xxx miles)

Thanks for the replies guys, it's really appreciated, my car is a 81 300SD. It's been sitting for a month waiting for new axles, it's such a bummer to not be able to drive it now after finally putting the new axles on, and to top it off it's sat long enough there's a rodent in there now eating my wires. I'm a little confused though, are the ports on top of the reservoir supposed to overflow, or is there something wrong with them if they do that?

Here's what I'm looking at, those two pegs go up and down easily, if I hold them down really firm with my fingers, fluid will not squirt out. It seems like those caps would have to fit really tight to hold them down well enough, are the caps meant to hold these pegs down or just to look nice?

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You are missing the rubber caps for the float switches. Replace missing caps, solve problem.

Thanks querty, I'm looking at the caps now, how do I know if it's an ATE or Lucas Girling reservoir?

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1981 W126 300SD

Buy your caps here....I ordered 2 new ones for my car....then I found a brand new reservoir at pick n pull....not having caps makes a horrible mess the number is 0004319087
http://www.pelicanparts.com/cgi-bin/ksearch/pel_search.cgi?SUPERCAT_FLAG=Y&make=MBZ&please_wait=N&forumid=&threadid=&command=DWsearch&description=0004319087&x=11&y=7

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